On some types of vehicles the necessity is felt to monitor the operating conditions of the tyres and to possibly keep traces of the evolution in time of some characteristic operating parameters.
Characteristic parameters that are generally considered may be identification code, temperature, pressure, distance run by the tyre, as well as parameters originating from mathematical calculations or signal processing that can be carried out within the tyre or on board the vehicle.
To this aim, within the tyre an electronic device can be mounted, said electronic device being suitable for obtaining at least one of the above characteristic parameters. Preferably, the electronic device can comprise an electronic unit and an antenna. The electronic unit can comprise at least one sensor, possibly associated with a control unit (such as a microprocessor) and/or a data storage unit. The electronic unit is preferably associated to an antenna, preferably said antenna has the task of enabling radio-frequency signal exchange with the devices mounted on board the vehicle.
In addition, the antenna can allow the system present within the tyre to be suitably powered without using independent powering units (e.g. batteries within the tyre). Therefore, the apparatus mounted on board the vehicle are provided to generate an electromagnetic field with which the antenna placed in the tyre can be coupled by induction, and by virtue of which the necessary energy for operation of the sensor and the possible control unit is supplied by the antenna itself.
EP 906,839 describes a method and apparatus for bonding an electronic monitoring device having electronic and mechanical components for monitoring at least one engineering condition within a tire to a vulcanized rubber patch which is secured to the inner cavity of a tire utilizing a layer of dual cure bonding rubber. The patch may be rubber selected from the group consisting of Ethylene Propylene Diene Monomer (EPDM) rubber, butyl rubber, natural rubber, neoprene and mixtures thereof. One preferred embodiment is a mixture of chlorobutyl rubber and natural rubber. Another preferred embodiment is a mixture of Styrene-Butadiene rubber (SBR) and natural rubber.
WO 2007/121,768 describes an electronic device (10), as illustrated in the Figures, which comprises an electronic unit (20), an antenna (30) connected with the electronic unit (20), and an anchoring body (40) comprising at least two portions (41). The anchoring body (40) is made of an elastomeric material selected from synthetic diene rubbers, natural rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber and the like.